Safety tank closure



J. H. DE F REES SAFETY TANK CLOSURE Nov. 7, 1950 INVENTOR. JOSEPH H.DEFREES BY $4M M Mom ATTORNEYS 0E dmvwvww mm mm Filed July 751 I948Patented Nov. 7, 1950 UNITED STATES PATENT OFFICE 2,529,329 SAFETY TANKCLOSURE Joseph H. De Frees, Warren, Pa.

Application July 31, 1948, Serial N 0. 41,790 3 Claims. (01. 2204.4)

This invention relates to safety tank closures, and more particularly toa combined vent valve, fill, and manhole cover for mobile gasolinetanks, such as are used upon delivery trucks.

One object ofthe invention is to provide a combined closure of thecharacter described, in which all parts are carried by a plate or discattachable directly to the metal shell of the tank itself, without theinterposition of a sleeve or ring between the two, enabling allnecessary securing parts, such as the nuts or attaching bolts, to bemounted exteriorly of the gasolinecontaining chamber, thereby avoidingany possibility of accident as the result of tool manipulation withinthe tank chamber at a time when explosive gases might be ,containedtherein.

A further object of the invention is to provide a combined closure ofthe character described, including all necessary vent or relief meansfor the flow;of air or gas either inwardly or outwardly through theclosure, and at both low and high pressures, soas to take care ofeventualities resulting fromvariations in pressure either internally orexternally of the tank, as well as danger arising when the tank tipsover, or from similar causes. I

Another object of the'invention is to provide a combined closure of thecharacter described, including a small vent valve unit, capable ofconvenient replacement and repair, attached to a filling openingclosure, the latter of which provides for maximum emergency vent reliefin cases where the pressure within the tank suddenly rises to anabnormal degree as in case of fire.

Finally, another object of the invention is to provide a combinedclosure of the character described, which is simple, efiective anddurable in operation, which can be made and applied at low cost, whichis capable of manipulation without special tools or appliances, andwhich safeuards the tank and its contents from most of the usual hazardsencounterd in vehicles of this kind.

Further objects of the invention in part are obvious and in part willappear more in detail hereinafter.

In the drawings, which represent one suitable embodiment of theinvention,

Fig. 1 is a plan view, illustrating one-half of the cover, of which theomitted half is a duplicate; r

Fig. 2 is a sectional elevation on the line 2-2, Fig. 1, the vent valvebeing shown in elevation;

Fig. 3 is a detailed section, on a larger scale, on the line 33, Fig. 2;and

Fig. 4 is a detailed sectional plan view on the line 44, Fig. 3.

The tank to which the closure forming the subject matter of the presentinvention is applied, indicated at I0, may be of any suitable form ordescription and is usually made of heavy sheet metal, of the order ofone-eighth of an inch in thickness, the tank as a whole being elongatedand of circular or oval crosssection.

The closure of the present invention includes a base disc or plate I l,of circular or oval form, a little larger than an opening l2 in the tankwall which it covers. Thus, the peripheral portion of the plate lloverlaps the edge of the opening [2, the overlapping portions of thecover and tank being sealed by a ring-form corkor other suitable gasketI 3. Base plate H is secured to the tank wall by a series of bolts I4,spaced peripherally around the opening and suppliedwith adjustableclamping nuts 15" and sealinggasket l6, preferably'copper coveredasbestos gaskets, and with lock washersll. Thus, at each bolt the coverand body are firmly and tightly clamped and sealed'together, preventingany possible leakage.

At any time, by taking. off thenuts IS, the plate H and all partssupportedby'it may be taken of; from the tank, the large ,opening l2serving as a manhole for accessto its interior. By opening the fillingopening later described, access may be had to the heads of bolts M toprevent them from falling into the tank cavity, but removal of theclosure involves no" tool manipulation within the tank chamber, such asmight cause a spark and ignite inflammable gases and cause an explosion.

The central portion of base plate H isprovided with a large filling andvent opening l8, around which the plate is turned up to form a generallycylindrical short neck or wall [9 fianged'inwardly at 20. Flange 20 isformed in a uniform fiat plane'even though the plate I I must be curvedto correspond to the contour of the wall In of the tank itself.

Adjacent to and outside of the wall Hi, the cover plate is provided withtwo pairs of upstanding ears, 20 at the left in Fig. 2 and 2| at theright. Ears 2i pivotally support a cross bar member 22, to theundersurface of which is secured a vent valve unit, marked generally 23and later described in detail. The far end of bar member 22 is providedwith a shoulder 24 and beyond it' with a curved tongue or extension 25.

Cooperating with bar 22 .is a looking or latch lever 2 6-pivota11yconnected to the ears 2!! and having a recess or opening 21 throughwhich the tongue 25 of bar 22 extends, when the parts are in closedposition, and also havinga transversely extending shoulder or abutment28,

- adapted, in closed position of the parts, to engage the shoulder 24and "thus 'releas'ably lock or latch the bar 22 in cover-closedposition.

The undersurface of bar 22 is provided with a. hollow central boss 30having several lateral openings 3|. This boss isinternally threaded toreceive the threaded portion of the vent valve unit 23. The head ofthevent valve unit clamps in place a disc valve or gasket member 32backed by a steeldisc diaphl'agm33, below whlchis cated a gasketretaining disc 34, spaced from gasket 32 by a spacing washer 35. l

The vent valve unit is shown in detail in Figs. 3 and 4. It comprises abody portion 36 threaded at 31 for securement to the boss -3t) andprovided with a noncircular or hex head 38. Body 36 is hollow and isprovided internally with several, four being shown, of internallongitudinal ribs 39 which form guides along which slides a poppet valvemember 40 biased upwardly in Fig. 3, against an annular seat 4| by alight compression spring 42.

The central portion of the poppet valve is of tubular form, the chambertherein, being provided with an upper ball valve member 43 seatingdownwardly, and with a lower ball valve member 431; normally inactiveand supported by an imperforate closure disc. The upper end of thechamber'is provided with a'disc 45 provided through ports or openings45.' 41 indicates a series of several small lateral relief ports oropenings in the lower portion of the central body of the poppet valvemember.

Figs. 2 and 3, together, illustrate the normal positions of all partswhen, the cover is fully closed, such as when the vehicle is traw nalong x V the road. Movement of latch lever 23 22 soas to app y thesealing disc froingasket32 to the flange with yielding jpressure,although the bar 22 has not beendepre'ssed sufiiciently to contact withthe backing plateior disc 33. Spring 42 holds the poppet valve elevatedand in closed position. Ballvalve 43 is. at rest closing the channelbeneath it, while ball valve 43a is also at restuponimperforat'edisc'fl. t Shouldf'the pressure within the tankrise asmall-amount, say one poundon so, for any reason, relief of the pressuretqatmosphereis afforded by way of the .vent valve, through ports 41, andthen upwardly-around ball 43, which it unseats, thencethrou'gnports and3| and out to atmosphere around, -the bar 26. I -lowever, should the.pressure within thetank rise abnormally, say about six, seven or morepounds, then the backing disc'33yieldsand .allows gasket 32 to rise awayfrom the flange 2D and open a wide vent around the disc-like gasketdirectly to atmosphere. Y I

Should the pressure within the tank fail, spring 42 yields and permitsthe poppet valve as a whole to move downwardly in Fig. 3, air thenflowing inwardly through ports 3| and downwardly around the outside ofthe poppetvalve in the spaces between the ribs 39 and thence to theinterior chamber. 4

Should the truck turn over, so that the vent valve is upside down, orpartially so, so that ball 43 is below ball 43a, then ball 43a moves toa seat at the opposite end of its chamber, closing off the ports 41 andpreventing loss of liquid through the vent valve' However, if with theparts in this positioniventing inwardly neces-. sary,- the valve'spiing12'agaitryields. permitting the poppet valve to move inwardly and.opena the latching position shown'has depressed the bar passage asbefore. Likewise, if; the pressure in i the .overturned tank arisesabnormally, such as because of fire, the large. disc '33 yields-andopens the larger vent-to thefoutsidegas before. l

The constructiondescribed not onlyprovides for, all, necessarysafeguarding vents, both in wardly .andfloutwardly butwalso provides a.tank closure-that requires no attachmentof-a or flange to thetankitself, and entirely dispenses with tool work on' the inside of the tankwhen removing or re-applying the closure thereto, thus avoidingaccident.

Other advantages of the invention will be apparent to those skilled inthe art.

What I claim is:

1. A combined vent valve and filling and manhole cover for mobilegasoline tanks, comprising a sheet metal base adapt-ed for attachment ofits peripheral portion to the metal around an opening in the tank wall,said plate being provided with an opening of relatively large diameter,an arm pivoted on said plate at one side of the opening therein andextending across said opening and provided at the center thereof with arecessed internally threaded boss, a cover for the tank wall openingseated upon said boss, and a generally cylindrical externally threadedvent valve unit extending through a central, opening in said cover andthreaded into the recess of said boss and having a shouldered head whichsecures the cover to the boss.

2. A combined vent valve and filling and manhole cover for mobilegasoline tanks, comprising a sheet metal base adapted for attachment ofits peripheral portion to the metal around an opening in the tank wall,said plate being provided with an opening of relatively large diameter,an arm pivoted on said plate at one side of the opening therein andextending across said opening and provided at the center thereof with arecessed internally threaded boss, a cover for the tank wall'opening'seated upon said boss, a generally cylindricalexternally threaded ventvalve unit extending through a central opening in said cover andthreaded into the recess of said boss and having a shouldered head whichsecures the cover to the boss, said vent valve unit including a tubularbody portion, and a yielding valve member seating outwardly and mountedwithin the bore thereof.

, 5 3. A combinedvent valve and filling and manhole cover for mobilegasoline tanks, comprising a sheet metal base adapted for attachment ofits peripheral portion to the metal around an opening in the tankwalLsaid plate being provided with an opening of relatively largediameter, an arm pivoted on said plate at one side of the openingtherein and extending across said opening and provided at the centerthereof with a recessed internally threaded boss, a cover for the tankwall opening seated upon said boss, a generally cylindrical externallythreaded vent valve unit extending through a central opening in saidcover and threaded into the recess of said boss and having a shoulderedhead which secures the cover to the boss, said vent valve unit includinga tubular body portion, a yielding valve member seating outwardl andmounted within the bore thereof,-and having a through passage, and twoyieldable check valves, one seating outwardly and the other inwardly;carried by said valvemember, and mounted in the through channel thereof.

r JOSEPH H. DE FREES.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,739,911 McMurray Dec. 17, 19291,893,942 Jensen Jan. 10, 1932 2,089,251 De Frees 'Aug. 10, 19372,169,410 Drane Aug. 15, 1939

